In prior art systems for computerized tomography and radiotherapy of the breast, the patient is horizontally positioned, while for mammography the patient may be positioned vertically. Systems with a horizontal patient in the prone position have an advantage of reduced exposure of organs other than the breast. A disadvantage of prone or supine systems is that they are not suitable for upright radiotherapy, wherein the patient or the source rotates about a vertical rotational axis, since the required source-axis-distance (SAD) in order to prevent collision of the patient's legs with the equipment is prohibitively large. Another disadvantage of such systems is the limited angular range of irradiating beams due to: a) excluding orientations where residual radiation may expose other organs and b) difficulty in blocking the residual radiation.